(1) Since I have been sailing for the past 30 years, it occurred to me there must be an easy way to control the mainsail of a sailboat. The mainsail of a sailboat has a tendency to thrash and flutter in heavy winds and makes the sailboat difficult to handle, as well as, having the sail blow over on to the deck or rails while raising or lowering. This invention is an easy to use device to control the mainsail so it will fold on to the boom and not allow the mainsail to drop to the deck, causing damage to the sail. This device is used when (1) raising the mainsail and (2) when lowering the mainsail. The device consists of 4 battens, two on each side of the boom, that slip into slots located in the center of the batten holder. The batten holders are secured to the boom by two screws in each holder.